Assessment of daily life physical activities in pulmonary arterial hypertension.

Vincent Mainguy,Didier Saey,Steeve Provencher,Simon Malenfant,François Maltais,Rory Edward Morty

doi:10.1371/journal.pone.0027993

Abstract

BackgroundIn pulmonary arterial hypertension (PAH), the six-minute walk test (6MWT) is believed to be representative of patient's daily life physical activities (DLPA). Whether DLPA are decreased in PAH and whether the 6MWT is representative of patient's DLPA remain unknown.Methods15 patients with idiopathic PAH (IPAH) and 10 patients with PAH associated with limited systemic sclerosis (PAH-SSc) were matched with 15 healthy control subjects and 10 patients with limited systemic sclerosis without PAH. Each subject completed a 6MWT. The mean number of daily steps and the mean energy expenditure and duration of physical activities >3 METs were assessed with a physical activity monitor for seven consecutive days and used as markers of DLPA.ResultsThe mean number of daily steps and the mean daily energy expenditure and duration of physical activities >3 METs were all reduced in PAH patients compared to their controls (all p<0.05). The mean number of daily steps correlated with the 6MWT distance for both IPAH and PAH-SSc patients (r = 0.76, p<0.01 and r = 0.85, p<0.01), respectively.ConclusionDLPA are decreased in PAH and correlate with the 6MWT distance. Functional exercise capacity may thus be a useful surrogate of DLPA in PAH.

Highlights

Pulmonary arterial hypertension (PAH) is characterized by a progressive increase in pulmonary vascular resistance leading to right heart failure and death
The aims of this study were to test the hypothesis that the level of daily life physical activities (DLPA) of pulmonary arterial hypertension (PAH) patients is markedly lower compared to sedentary healthy subjects, and that the 6MWT could be a useful surrogate of DLPA among PAH patients
Table legend: yr, years; F, female; M, male; BMI, body mass index; kg, kilogram; RAP, right atrial pressure; mPAP, mean pulmonary artery pressure; PCWP, pulmonary capillary wedge pressure; CI, cardiac index; PVRi, pulmonary vascular resistance index; WU, Wood units; NYHA, New York Heart Association; 6MWT, six-minute walk test; m, meters; % pred, percentage of predicted value; CTRL, healthy control subjects; idiopathic PAH (IPAH), patients with idiopathic pulmonary arterial hypertension; SSc, subjects with limited systemic sclerosis without PAH; PAH associated with limited systemic sclerosis (PAHSSc), patients with pulmonary arterial hypertension associated with limited systemic sclerosis. doi:10.1371/journal.pone.0027993.t001

Summary

Introduction

Pulmonary arterial hypertension (PAH) is characterized by a progressive increase in pulmonary vascular resistance leading to right heart failure and death. In PAH, exercise tolerance is most commonly assessed by the six-minute walk test (6MWT), with the assumption that the distance walked during this test is representative of patient’s daily life activities [8]. The relationship between the distance walked during the 6MWT and the level of daily life physical activities (DLPA) has not been documented in PAH. Decreased level of DLPA has been subjectively reported by PAH patients [9]. Whether PAH patients are objectively less physically active to a level that may theoretically contribute to deconditioning remains unknown. In pulmonary arterial hypertension (PAH), the six-minute walk test (6MWT) is believed to be representative of patient’s daily life physical activities (DLPA). Whether DLPA are decreased in PAH and whether the 6MWT is representative of patient’s DLPA remain unknown

Objectives

Methods

Results

Conclusion